Comparison of Queuing Disciplines for Differentiated Services Using OPNET

As part of the resource allocation mechanisms, each router must implement some queuing discipline that governs how packets are buffered while waiting to be transmitted. Various queuing disciplines can be used to control which packets get transmitted (bandwidth allocation) and which packets get dropped (buffer space). The queuing discipline also affects the latency experienced by a packet, by determining how long a packet waits to be transmitted. Examples of the common queuing disciplines are first-in first-out (FIFO) queuing, priority queuing (PQ), and weighted-fair queuing (WFQ). This paper throws a light on the comparative study of these disciplines and explains through simulation which is a better method of queuing.